The Mannheim–Stuttgart high-speed railway is a 99 km (62 mi) long railway line in Germany, connecting the cities of Mannheim and Stuttgart. The line was officially opened on 9 May 1991, and Intercity-Express service began on 2 June. The Hanover–Würzburg high-speed railway also opened at the same time. The line cost about DM 4.5 billion to build and has 15 tunnels and more than 90 bridges.

Mannheim, officially the University City of Mannheim, is the second-largest city in the German state of Baden-Württemberg, after the state capital of Stuttgart, and Germany's 21st-largest city, with a 2021 population of 311,831 inhabitants. The city is the cultural and economic centre of the Rhine-Neckar Metropolitan Region, Germany's seventh-largest metropolitan region with nearly 2.4 million inhabitants and over 900,000 employees.